Double walled high voltage insulator cover for mitigating leakage current

Abstract

For protecting wildlife from high voltage conductors proximate to a utility pole, dielectric covers are used to cover fuse cutouts, bushings, or other connections to insulators. Such covers include a vertical slot for receiving an energized wire so the cover can be installed using a hot-stick while the wire is energized. To eliminate leakage currents flowing across the cover under high voltage conditions, which previously led to localized melting of the cover, inner walls of the cover are molded that are laterally separated from the outer walls of the cover. The double wall design eliminates leakage currents due to the extra dielectric wall and air gap, and the inner wall is not subject to contamination from conductive pollutants. The double wall design also increases the insulating properties of the cover.

What is claimed is: 
     
       1. A wildlife protection system for a high voltage power system comprising:
 a dielectric cover configured to fit over a high voltage conductor to prevent access to the conductor by wildlife, the cover having a top portion when installed over the conductor, 
 wherein the cover has outer walls that extend down from the top portion of the cover to at least partially surround the conductor, and 
 wherein the cover has inner walls that extend down from the top portion of the cover, the inner walls being separated from the outer walls by an air gap to form portions of the cover with double walls laterally surrounding the conductor. 
 
     
     
       2. The system of  claim 1  wherein the cover is a fuse cutout cover. 
     
     
       3. The system of  claim 1  wherein the cover covers a portion of an insulator. 
     
     
       4. The system of  claim 1  wherein the cover is a bushing cover. 
     
     
       5. The system of  claim 1  wherein the inner walls oppose only a portion of the outer walls. 
     
     
       6. The system of  claim 1  wherein the cover is a fuse cutout cover and the cover includes a vertical slot for a wire, and wherein the inner walls extend substantially between the slot and the fuse. 
     
     
       7. The system of  claim 1  wherein the cover is installed over a fuse cutout, wherein the cutout comprises:
 an insulator; 
 a first connector, supported by the insulator, for a wire carrying a voltage; and 
 an openable fuse electrically connected to the first connector, 
 wherein the inner walls of the cover at least partially shroud the first connector. 
 
     
     
       8. The system of  claim 1  wherein the inner walls reduce leakage currents across the cover. 
     
     
       9. The system of  claim 1  wherein the cover has one or more through holes for retaining pins, and wherein the inner walls do not block the through holes for the retaining pins. 
     
     
       10. The system of  claim 1  wherein the inner walls terminate above a bottom edge of the cover. 
     
     
       11. The system of  claim 1  wherein the cover is positioned to cover at least a top of an insulator supported by a utility pole or a crossarm. 
     
     
       12. The system of  claim 1  wherein the cover has a slot for receiving a wire to allow the cover to be installed while the wire is energized. 
     
     
       13. The system of  claim 12  wherein the slot is substantially facing a utility pole or crossarm. 
     
     
       14. The system of  claim 1  wherein the cover is packaged in the same package as a fuse cutout while the cover is fitted over the cutout. 
     
     
       15. A method for using a wildlife protection system for a high voltage power system comprising:
 providing a dielectric cover, the cover having a slot for receiving a wire, the dielectric cover being configured to fit over a high voltage connector for the wire to prevent access to the connector by wildlife, the cover having a top portion when installed over the connector, wherein the cover has outer walls that extend down from the top portion of the cover to at least partially surround the connector, and wherein the cover has inner walls that extend down from the top portion of the cover, the inner walls being separated from the outer walls by an air gap to form portions of the cover with double walls laterally surrounding the connector; and 
 fitting the cover over the wire to at least shroud the connector for the wire. 
 
     
     
       16. The method of  claim 15  wherein the cover is a fuse cutout cover. 
     
     
       17. The method of  claim 15  wherein the cover covers a portion of an insulator. 
     
     
       18. The method of  claim 15  wherein the cover is a bushing cover. 
     
     
       19. The method of  claim 15  wherein the cover includes one or more through holes in it for receiving one or more retaining pins, the method further comprising pushing one or more retaining pins through the one or more holes to secure the cover in place over the cover. 
     
     
       20. The method of  claim 19  wherein the inner walls do not block the holes for receiving the one or more retaining pins.